Component Function Check

WARNING: This page is about a different car, the 2019 Nissan NV3500 HD, 2019 Nissan NV2500 HD, and 2019 Nissan NV1500. However, it is still accessible from the selected car via links, so may be relevant.

Whenever system's high and/or low side pressure is abnormal, diagnose using a manifold gauge. The marker above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the standard (usual) pressure, however, differs from vehicle to vehicle, refer to Inspection (Ambient air temperature-to-operating pressure table).

Low-pressure Side Becomes Negative

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

Low-pressure side becomes negative.

Courtesy of NISSAN NORTH AMERICA, INC.

Liquid tank or front/rear side of expansion valve's pipe is frosted or dewed.

High-pressure side is closed and refrigerant does not flow.

Expansion valve or liquid tank is frosted.

Leave the system at rest until no frost is present. Start it again to check whether or not the malfunction is caused by water or foreign particles.

If water is the cause, initially cooling is okay. Then the water freezes causing a blockage. Drain water from refrigerant or replace refrigerant.
If due to foreign particles, remove expansion valve and remove the particles with dry and compressed air (not shop air).
If either of the above methods cannot correct the malfunction, replace expansion valve.
Replace liquid tank. Refer to Removal and Installation .
Check oil for contamination.